1. Field of the Invention
The present invention relates to electrical cable connectors and, more particularly, to electrical cable connectors that include sealing assemblies to prevent leakage of fluids into or from the electrical cable or the electrical device connected thereto.
2. Setting of the Invention
Electrical cable connectors are used to connect an electrical power transmission cable to an electrical device, such as a motor. When such connectors are used in wellbore environments, the prevention of leakage of fluids from within the wellbore into the cable or the motor at the point of connection is extremly important. Fluid leakage into the windings of the motor of an electrical submergible pump (ESP) is one of the primary causes of premature ESP failure. Such failures result in many millions of dollars in lost revenue caused by the wellbores being deactivated for replacement of the defective ESP's, as well as many thousands of dollars in ESP repair or replacement costs. There is a critical need to have an effective sealing system associated with the electrical cable connectors to prevent this leakage of fluids.
Various prior electrical cable connectors are disclosed in U.S. Pat. Nos. 2,382,117; 4,128,735; and 4,679,875, all commonly assigned to the assignee of the present invention. Of interest is an electrical cable connector with a flowable sealing mechanism disclosed in U.S. Pat. No. 4,927,386. In the '386 Patent a sealing plug of substantially uncured flowable, incompressible seal material is disposed in a connector housing. Movable discs exert pressure on the sealing plug so that the flowable material will flow into any otherwise empty spaces between the discs and a cable and the housing.
While the flowable sealing mechanism of the '386 Patent may initially perform adequately in preventing leakage of fluids, experience has shown that at typically encountered wellbore temperatures and conditions, e.g. up to 400 degrees F., 3000 PSI and hydrogen sulfide over many months with temperature cycling caused by on/off operation of ESP Motor, the once uncured and flowable material used will in fact become "cooked" and thereby become cured and nonflowable. Thus, the sealing mechanism disclosed in the '386 Patent will not function as intended and may provide a path for undesired fluid leakage.
There is a need for an electrical cable connector that will prevent fluid leakage in typically encountered wellbore environment.